There is safety in numbers and obvious physical advantages in having someone else there if you are injured or weak. But there are other advantages to being in a group when you are in a survival situation. The greatest is that there are more individuals to take care of the necessary tasks of day-to-day living. Not only do many hands make light work, but the various individuals in the party are bound to have different strengths and weaknesses. If you are someone who is good at building a shelter but less proficient at finding wild edibles, for example, being part of a group allows you to put all your efforts into providing an effective group shelter, while feeling secure that other people in the group will provide other necessities such as food, water and fire.

There are also a few disadvantages, however. Now you have to provide not only for yourself, but for the whole group. If all the other group members have a certain amount of outdoor skills and there are plenty of resources around,  this may not be a difficulty, but if you are the only one with any survival skills or if there aren't many supplies available, it can be very hard to ensure the whole group is well hydrated, fed and comfortable. It may also happen that one member of the group is injured and needs taking care of. After all, the chain is only as strong as its weakest link.